Field of the Invention
The present invention relates to movable cooking appliances or cooking trays including structure which is adapted to be placed on a worktop of kitchen furniture or inside a cooking oven (collectively referred to as a cooking unit), and includes a heating element and releasable connector means for making electrical connection with power supply connector means. With the term “movable” we mean any kind of cooking and heating appliance which can be plugged or unplugged to a fixed support, whatever such support is.
Description of the Related Art
The above kind of cooking appliances or cooking accessories are well known in the art. An example is shown in U.S. Pat. No. 5,272,317. With the known appliances the heating element is an electrical resistance heater connected, for instance, to a shelf or tray adapted to be introduced into an oven cavity. The use of electrical resistance heaters has been replaced by more efficient induction heating elements which, despite a higher complexity and cost (mainly due to the complex electronic driving circuit), allow the induction heating elements to reach a desired temperature in a shorter time and with a lower energy consumption. One compromise would be to design an induction cooking appliance or accessory without a built-in electronic driving circuit, and integrating this in kitchen furniture or cooking appliance (such as a traditional oven or an induction oven). By adopting this solution it is important to assure a safe and reliable connection between the “fixed” electronic driving circuit and the movable induction cooking appliance or accessory.
Prior art connectors that are in use generally have terminals with equal length. The design of these connectors doesn't implement any further safety feature that guarantees power supply cut-off when the user is extracting the removable tray with an induction heater while the tray is working. This abnormal procedure may happen during the use of the oven and this can cause a potential risk of electric arcing at the power terminals and potential breakdown of the insulated gate bipolar transistor (IGBT) associated with the electronic driving circuit of the heating element.